Expression of EGFR and molecules downstream to PI3K/Akt, Raf-1-MEK-1-MAP (Erk1/2), and JAK (STAT3) pathways in invasive lung adenocarcinomas resected at a single institution

Mutant Proteomics of Lung Adenocarcinomas Harboring Different EGFR Mutations

Epidermal growth factor receptor EGFR major driver mutations may affect downstream molecular networks and pathways, which would influence treatment outcomes of non-small cell lung cancer (NSCLC). This study aimed to unveil profiles of mutant proteins expressed in lung adenocarcinomas of 36 patients harboring representative driver EGFR mutations (Ex19del, nine; L858R, nine; no Ex19del/L858R, 18). Surprisingly, the orthogonal partial least squares discriminant analysis performed for identified mutant proteins demonstrated the profound differences in distance among the different EGFR mutation groups, suggesting that cancer cells harboring L858R or Ex19del emerge from cellular origins different from L858R/Ex19del-negative cells. Weighted gene coexpression network analysis, together with over-representative analysis, identified 18 coexpressed modules and their eigen proteins. Pathways enriched differentially for both the L858R and Ex19del mutations included carboxylic acid metabolic process, cell cycle, developmental biology, cellular responses to stress, mitotic prophase, cell proliferation, growth, epithelial to mesenchymal transition (EMT), and immune system. The IPA causal network analysis identified the highly activated networks of PARPBP, HOXA1, and APH1 under the L858R mutation, whereas those of ASGR1, APEX1, BUB1, and MAPK10 were highly activated under the Ex19del mutation. Interestingly, the downregulated causal network of osimertinib intervention showed the highest significance in overlap p-value among most causal networks predicted under the L858R mutation. We also identified the causal network of MAPK interacting serine/threonine kinase 1/2 (MNK1/2) highly activated differentially under the L858R mutation. Tumor-suppressor AMOT, a component of the Hippo pathways, was highly inhibited commonly under both L858R and Ex19del mutations. Our results could identify disease-related protein molecular networks from the landscape of single amino acid variants. Our findings may help identify potential therapeutic targets and develop therapeutic strategies to improve patient outcomes.

Emodin sensitizes human pancreatic cancer cells to EGFR inhibitor through suppressing Stat3 signaling pathway

Background

Excessive expression of EGFR is closely related to tumor formation, transfer and deterioration, which has attracted much attention. EGFR overexpression may be detected in up to 90% of pancreatic tumors. However, drug resistance of EGFR inhibitors targeting treatment severely limits its clinical application.

Methods

In this study, Western blotting was used to detect the expression of p-Stat3, EGFR, Bcl-2, cleaved-caspase3 and Bax. Cell apoptosis was evaluated via flow cytometry. The colon assay and MTT assay were applied for detecting the cell proliferation in vitro. The xenograft mouse model was used to examine the cell proliferation in vivo.

Results

Emodin remarkably enhanced the anti-cancer effect of EGFR inhibitor on pancreatic cancer cells. In addition, emodin promoted afatinib-induced apoptosis by inhibiting the Stat3 signaling pathway. Meanwhile, siRNAs against Stat3 significantly increased the apoptosis of pancreatic cancer cells. EGFR inhibitor promoted phosphorylation of Stat3 in pancreatic cancer cells. Interestingly, emodin combined with EGFR inhibitor inhibited the proliferation of pancreatic cancer cells in vitro. The tumor xenograft mice model was further confirmed that emodin possessed a synergy anticancer effect with afatinib on pancreatic cancer cells by regulating the Stat3 expression.

Conclusion

These results indicate that the combination of emodin with EGFR inhibitor is an effective therapeutic strategy to sensitize human pancreatic cancer.

miRNA-223 is an anticancer gene in human non-small cell lung cancer through the PI3K/AKT pathway by targeting EGFR

The present study aimed to further explore the molecular mechanisms of miRNA-223 in non-small cell lung cancer (NSCLC). Data prospectively collected from NSCLC patients and volunteers from March 2016 to May 2016 at Tsinghua Changgung Hospital were analyzed. Cell proliferation was measured using MTT assay, while cell apoptosis and caspase-3/9 activity were measured using flow cytometry and caspase-3/9 activity kit. Bax, EGFR, PI3K and p-Akt protein were also investigated using western blotting. The results revealed that the serum levels of miRNA-223 in NSCLC patients were downregulated. In an in vitro model, overexpression of miRNA-223 induced apoptosis while reducing cell proliferation. In contrast, downregulation of the expression of miRNA-223 inhibited apoptosis whereas it increased cell proliferation. Meanwhile, overexpression of miRNA-223 suppressed the protein expression of EGFR, PI3K and p-Akt in NSCLC cells. An EGFR inhibitor promoted the anticancer effects of miRNA-223 in NSCLC cells through the EGFR/PI3K/AKT pathway. Meanwhile, a PI3K inhibitor increased the anticancer effects of miRNA-223 in NSCLC cells through the PI3K/AKT pathway. Thus, a new pathway has been identified in the present study, and application of miRNA-223 may induce the apoptosis of NSCLC through the PI3K/AKT pathway by EGFR.

Activation of Janus kinase 1 confers poor prognosis in patients with non-small cell lung cancer

The activation of Janus kinase 1 (JAK1) has been reported to occur in non-small cell lung cancer (NSCLC), activating the JAK/signal transducers and activators of transcription cascade. However, the association between JAK1 activation and the prognostic value in NSCLC remains unclear. The present study initially investigated the association between expression of the activated form of JAK1 (p-JAK1) and prognosis in patients with NSCLC. A cohort of 142 resected primary NSCLC tissue samples, including 74 adenocarcinoma (ADCC) and 68 squamous cell carcinoma samples, were analyzed. p-JAK1 expression status was determined by immunohistochemistry. Evaluation of epidermal growth factor receptor (EGFR) gene amplification by fluorescence in situ hybridization was subsequently performed in 74 ADCC samples. The prognostic significance of p-JAK1 expression and EGFR gene amplification were evaluated with univariate and multivariate survival analyses. Compared with normal lung tissue, p-JAK1 expression level was significantly increased in NSCLC (P<0.001). Positive p-JAK1 expression indicated a poor prognosis, particularly for patients in early stages (stage I/II, including tumor size <3 cm, Lymph node invasion N0/1; all P<0.05). p-JAK1 expression was an independent predictor of a poor prognosis (P=0.022). The overall survival time for patients with positive p-JAK1 expression and EGFR-amplified tumors was significantly shortened compared with patients with tumors negative for one or both features (both features present vs. neither feature present, P<0.001). The results provided clinical evidence that the activation of JAK1 was an independent prognostic factor, particularly in early stage NSCLC. The combination of EGFR gene amplification and p-JAK1 expression may be a novel target for the selection of individual therapy strategies and predicting the effects of therapy for NSCLC.